Sewing-machine.



J. LEATHEM. SEWINGUMAGHINE.

APPLICATION FILED DEC. 28, 1910. 1,017,567, Patented Feb. 13, 1912.

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wiimaooeo J. LEATHEM.

SEWING MACHINE.

APPLICATION FILED DEC. 28, 1910.

Patented Feb. 13, 1912.

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SAT 5 PATENT OFFICE.

JAMES LEATI-IEIVI, OF NEW YORK, N. Y., ASSIGNOR 'IO HERMANN, AUKAM 81; CO1, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

SEWING-MACHINE.

Specification of Letters Patent.

Application filed December 28, 1910.

Patented Feb. 13, 1912.

Serial No. 599,649.

To all whom it may concern:

Be it known that I, JAMES Lnn'rrrmr, a citizen of the United States, and a resident of New York, in the county of Richmond and State of New York, have invented certain new and useful Improvements in Sewing vlachines, of which the following is a specification.

This invention relates to sewing machines, more particularly to the needle motions for such machines, and the objects of the invention are to improve the construction of such machines and increase their efliciency of operation.

Other objects of the invention are to provide a needle motion for hem stitching or other similar stitching machines which can be run at very high speeds. A

While the invention is to be described with particular reference to a machine for making a hem stitch, the same is not to be considered as limited thereto, as many and various changes may be made, and the same may be embodied in widely varying forms without limiting the invention to the construction shown and described.

According to my invention the general structure of a sewing machine is not affected, the machine comprising as is usual, a bed plate, an overhanging arm, a needle bar mounted to reciprocate up and down in the end of the arm, means for so reciprocating it, and the usual needle plate, feed mechanism, etc.

In the present instance the needle bar is arranged to carry an actuating shaft provided with a cam, which actuates a needle holder secured to the end of the needle bar, suitable means being provided for turning said actuating shaft and reciprocating said needle bar.

The accompanying drawings illustrate one embodiment of my invention, such as above described.

In the drawings: Figure 1 is a side elevation with parts broken away, of a machine showing one embodiment of my invention; Fig. 2 is an enlarged detail View, partly in section, and with parts broken away, of the needle bar and its connections; Fig. 3 is an enlarged detail View in cross section of the end of the needle bar in position to place the first stitch off the hem fold; Fig. 4 is a view similar to Fig. 3, showing the needle bar in position to place a ing in addition, the position of a stitch on the hem fold and another one off the hem fold; Figs. 7, 8 and 9 are transverse sectional views through the cam on the actuating shaft showing the three respective positions of the cam for making a series of three stitches.

Referring to the drawings, A designates the bed plate, B the overhanging arm in which is mounted the needle bar actuating shaft or driving shaft C, to the end of which is secured the hub D, provided with the peripheral cam slot E which actuates a suitable take up lever F which in the present instance is shown in cross-section.

The needle bar 1 is mounted in the head J, and is reciprocated by means of a link 2, one end of which is pivoted to the hub D, and the other end of which is pivoted to the collar 3 secured to the needle bar 1. The needle bar 1 is made hollow throughout its length so as to contain the actuating shaft 4-, to the upper end of which is secured a set screw provided with a collar 5, which bears upon the top of the needle bar 1, said collar being provided with a feat-her 6, which is arranged to engage a vertical groove 7 on the inner side of an actuating sleeve 8, which, with the actuating shaft 4,

is adapted to rotate about the axis of the needle-bar 1, which latter is held against rotation by means of the collar 3 secured to the link 2, as before described.

The actuating shaft at is provided near its lower end with a circular shoulder 9, which fits into a corresponding recess in the needle bar 1, so that the actuating shaft 4 is held from moving vertically in relation to the needle-bar 1, by means of a collar 5 at one end, and the shoulder 9 at the other end, but at the same time may be rotated.

The actuating sleeve 8 is rotatably mounted in a suitable bearing 10, on the head J of the machine, and is held in position by means of a cap 11, secured to the top of the sleeve, which bears upon the top of the bearing 10, and a flange or collar 12, also secured to the actuatingsleeve 8, which bears against the bottom of the bearing 10.

Suitably secured to the actuating sleeve 8, by means of a set screw 13, is a bevel gear 14 which meshes with a bevel pinion 15 secured to one end of an arm 16, the other end of which is secured to the hub D through the medium of a pin 17, upon which one end of the link 2 is pivoted as before referred to. The pin 17 is held in position in the hub D by means of a set screw 18. From the above it will be seen that as the I hub D turns in the operation of the machine, the needle bar 1 will be reciprocated up and down through the medium of the link 2, whereas the actuating-sleeve 8 will be rotated through the medium of the pin ion 15, which is mounted concentrically in relation to the hub D and the needle bar actuating shaft C, the pinion 15, in the present instance, being of such size in relation to the gear 14, that the actuating sleeve 8 is turned, together with the actuating shaft 4, a third of a revolution for each reciprocation of the needle bar.

In the lower end of the needle-bar 1, in the present instance, is secured a cylindrical block 20, by means of a set screw 21. The cylindrical block 20 is provided centrally with a hole 22 in which is pivotally mounted a needle holder 23 by means of a pivot pin 24, the hole 22 being made sufficiently large to permit the needle holder to move back and forth a short distance about the pivot pin 24. The upper end of the needle holder 23 is provided with projecting portions 25 which fit in corresponding grooves 26 in the cylindrical block 20, the grooves 26 being of greater depth than the project ing portions 25 to permit the needle holder to move back and forth a short distance as before referred to. Suitably secured to one of the projecting portions 25 is a pin 27 upon which is mounted a roller 28 which engages a cam 29 secured to the lower end of the actuating shaft 4, the roller 28 being kept in contact with the surface of the cam 29 by the action of a spring 30, suitably embedded in the cylindrical block 20. The holder 23 is provided with a needle 30 the throw of which is controlled by the action of the cam 29 which is continually rotated by the actuating shaft 4 during the reciprocation of the needle, as before described.

If itis desired to hem-stitch some material by means of the needle motion above described, it is necessary that the machine should be provided with a suitable feeding mechanism, commonly used in 'hemstitching machines, which is capable of imparting one backward-feed movement to the material alternating with two forward-feed movements, so that two stitches can be placed off the hem fold and one on. The operation of the needle motion to produce the hem-stitch is as follows; it being assumed that the actuating shaft 4 rotates the cam 29, to which it is secured, a third of a revolution during each reciprocation of the needle bar, and that the cam 29 is so set that it is in the position shown in Figs.

3 and 7, when the needle bar is in its lower position to place the first stitch off the hem. It is also to be assumed that the material is in such a position on the bed plate of the machine that the needle will enter the material, shown in Fig. 5, at the point designated a, to produce the first stitch off the hem-fold, when the needle has reached the position shown in Fig. 3. After the first stitch has been made, the needle is raised to its uppermost position and again descends to its lower position, having in the meantime turned the actuating shaft and the cam to which it is secured a third of a revolution, as shown in Fig. 8, the material during the reciprocation of the needle bar having been fed backward so that the needle enters the material at the point des ignated b in Fig. 5, to produce the second stitch off the hem fold. After the second stitch has been made, the needle bar is again reciprocated, the actuating shaft together with the cam having in the meantime been turned another third of a revolution, as shown in Figs. 4 and 9, the material in the meantime having been fed forward so that the needle enters the material at the point designated 0 in Fig. 6, to produce the first stitch on the hem fold. During the next reciprocation of the needle bar the actuating shaft again rotates a third of a revolution, the cam again assuming the position shown in Figs. 3 and 7, whereas the .material is fed forward another step so that the needle enters the material at the point designated a in Fig. 6. Vhen the needle bar again reciprocates the actuating shaft rotates the cam to the position shown in Fig. 8, whereas the material is fed backward one step and another stitch is made at the point designated a. In the further operation of the machine the material is next fed forward two steps corresponding with two reciprocations of the needle bar to place another stitch on the hem fold and another 05 the hem fold.

In the present instance it is to be noted that the cam 29 is made circular in shape with the exception of two flat surfaces 40 and 41, the circular surfaces of the cam being designated by the numerals 42 and 43. It is also to be noted that the roller 28 is situated respectively at approximately the center of the flat surfaces 41 and 41, and the center of the circular surface 43 as shown in Figs. 7, 8 and 9 when the needle enters the material to make the stitches a, b and c, as before described. As it is necessary for the needle to travel downward after entering the material in order to engage the shuttle, in the reciprocation of the needle bar, it will be seen that just after the needle enters the material for the first stitch designated a, the

cam, in its rotation from the position shown in Fig. 7, while the needle bar is reciprocating to its lowermost position, will force the needle to the right to more easily engage the shuttle. It is also to be seen that the needle is again forced to the right after entering the material to produce the stitch designated 5, the cam being in the position shown in Fig. 8, when the needle enters the material, and in the further downward reciprocation of the needle to engage the shuttle moves to the right, as before described, in the same manner as was done in making the stitch designated a. When, however, the stitch 0 is made, the needle is kept in the same relative position after entering the material due to the roller engaging the circular surface 43, as shown in Fig. 9, until the needle, in the reciprocation of the needle bar, is withdrawn from the material.

From the above it will be seen that when the cam is shaped as above described, the needle in its three consecutive lowermost positions will reach approximately the same position and thereby avoid any possibility of not engaging the shuttle on any of a series of stitches. If, instead of the feeding mechanism just referred to, a feeding mechanism is used which feeds the material continually forward one step for each three reciprocations of the needle bar, the well known Gegauf stitch can be made with the needle motion just described.

What I claim is 1. A needle mechanism for sewing machines comprising in combination a reciprocating needle bar, an actuating shaft rotata bly mounted therein, a needle holder pivotally mounted on said needle bar, and cam means connected to said shaft for actuating said needle holder, and means for continually rotating said actuating shaft in one direction.

2. A needle mechanism for sewing machines comprising in combination a reciprocating needle bar, an actuating shaft rotatably mounted therein, a needle holder pivotally mounted on said needle bar and cam means connected to the end of said shaft for actuating said needle holder, said cam means being arranged to vary the position of the needle holder on each of a series of reciprocations of the needle bar and means for continually rotating said actuating shaft.

3. A needle mechanism for sewing machines comprising in combination a reciprocating needle bar, an actuating shaft rotatably mounted therein, a needle holder pivotally mounted on said needle bar, and cam means connected to said shaft for ac tuating said needle holder, said means being arranged to vary the position of the needle holder on each of a series of reciprocations of the needle bar, and means for continually rotating said actuating shaft a part of a revolution for each reciprocation of the needle bar.

4:. A needle mechanism for sewing machines comprising in combination a reciprocating needle bar, an actuating shaft rotatably mounted therein, a needle holder pivotally mounted on said needle bar, a cam secured to said shaft, means for keeping said holder in contact with said cam and means for continually rotating said actuating shaft.

5. A needle mechanism for sewing machines comprising in combination a reciprocating needle bar, an actuating shaft rotatably mounted therein, a needle holder pivotally mounted on said needle bar, and spring acting means for keeping said holder in contact with said cam.

6. A needle mechanism for sewing machines comprising in combination a reciprocating needle bar, an actuating shaft rotatably mounted therein, a needle holder pivotally mounted on said needle bar, cam means connected to said shaft for operating said holder, means for continually rotating said actuating shaft a third of a revolution for each reciprocation of the needle bar, said cam means being arranged to vibrate said holder to produce a hem stitch when the material is fed backward one step alternating with being fed forward two steps.

7. A needle mechanism for sewing machines comprising in combination a reciprocating needle bar, an actuating shaft rotatably mounted therein, a needle holder pivotally mounted on said needle bar, cam means connected to said shaft for operating said holder, means for continually rotating said actuating shaft a third of a revolution for each reciprocation of the needle bar, said cam means being arranged to vibrate said holder and to bring the end of the needle approximately always to the same position at the end of a series of reciprocations of the needle bar, as and for the purposes set forth.

8. A needle mechanism for sewing machines comprising in combination a reciprocating needle bar, an actuating shaft rotatably mounted therein, a needle holder pivotally mounted on said needle bar atright angles thereto, and cam means connected to the lower end of said shaft for actuating said holder.

9. A needle mechanism for sewing machines comprising in combination a reciprocating needle bar, an actuating shaft rotataloly mounted therein, a needle holder pivotally mounted on said needle bar at right angles thereto, a projection on said holder, and a cam on the lower end of said shaft which engages said projection for actuating said holder.

10. A needle mechanism for sewing machines comprising a needle bar, a needle holder pivotally mounted on said needle bar,

an actuating shaft rotatably mounted on In testimony whereof I have signed this said needle bar, the pivotal axis of said specification in the presence of two sub- 10 holder being substantially at right angles scribing Witnesses.

to the axis of the needle bar, and cam means for oscillating said needle holder about said JAMES LEATHEM' axis comprising a cam and a follower there- WVitnesses:

for, one mounted on the needle holder, the LEO J. lVLi'r'rY,

other on the rotatable actuating shaft. F. J. CRYSTAL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

